Patent GB-888241-A (GB)
Title: Improvements in or relating to web aligning means
IPC: D21F1/36
Filed: 1959-04-10
Abstract: 888,241. Automatic position control systems. EIMCO CORPORATION. April 10, 1959 [Aug. 1, 1958], No. 12210/59. Class 38 (4). [Also in Groups I and XVI] Web guiding apparatus comprises a roller having a substantially continuous cylindrical surface and including an axially immovable websupporting surface and an axially displaceable web-supporting arcuate member, the members being arranged so that the web is supported alternately solely by one member or the other, web position sensing means, means responsive to the sensing means on occurrence of lateral deviation of the web and operative during one portion of a revolution of the roller to effect axial displacement of the displaceable arcuate member out of lateral alignment with the axially immovable member, and means operative during another portion of the revolution of the roller for returning the axially displaceable member into alignment with the axiallyimmovable member, the axial displacement and return movements of the axially displaceable member being timed so that the web, while supported by the axially displaceable member, is shifted laterally, to align the web relatively to the axially immovable member. As applied to apparatus for guiding an endless web 18, Fig. 1 (not shown), of filter material, e.g. woven fabric, metallic screen or other permeable material, the web passes around a roller 24 which may be a driven or idler roller and past sensing means 28 for detecting lateral displacements of the web. The guiding roller (see Group XVI) has an axially immovable semi-cylindrical part 42, Figs. 2 and 3 (not shown), and a similar axially displaceable part 44. Solenoids 106, 108, Fig. 6, are connected to normally open switches 144 and 148. The switches 144, 148 have actuators 152, 154 respectively positioned adjacent each edge of the web 18, such that lateral movement of the web 18 from a central position closes the respective switch 144 or 148 to energize the solenoid 106 or 108, thereby causing the energized solenoid to actuate the movable part 44, Figs. 2 and 3 (not shown) of the 24. In a modification, Fig. 11 (not shown), the shaft 74 is moved axially by a ram 194 supplied with fluid under pressure through valves 200, 202 actuated by solenoids 210, 212, respectively energized upon closure of switches arranged at either edge of the web. In a further embodiment, Figs. 12 to 14 (not shown), rings 220, 222 operate switch-actuating arms 238, 252 and 240, 256 of normally-open switches 234, 248, 236 and 250, respectively, in circuit with solenoids 278, 288 actuating valves 272, 282 supplying a ram 264 with fluid under pressure. The piston-rod 260 of the ram 264 is connected through a coupling 263 with one shaft 74. Web sensing may be effected alternatively by rotary switches 350, 352, Fig. 15 (not shown), rotated by cores 340, 342 engageable with the web, by a double-pole plunger switch 262, Fig. 16 (not shown), spring-urged into contact with one edge of the web, by a double-pole pivoted arm switch 288, or by photo-electric cells positioned adjacent the lateral edges of the web.